Internal combustion engines that utilize spark ignition combustion processes commonly include an ignition coil that is dedicated to a single spark plug. The ignition coil is used to develop a spark-initiating current that is sent to the spark plug, thereby allowing the spark plug to generate a spark which initiates combustion of a fuel and air mixture within a combustion chamber of the internal combustion engine. The ignition coil has three basic interfaces with the internal combustion engine: 1) a mounting boss which typically receives a fastener to clamp the ignition coil to the internal combustion engine, 2) a low-voltage connector body which mates with a mating connector of the internal combustion engine to power the ignition coil, and 3) a high-voltage tower which engages the spark plug and contains a conductor which delivers the spark-initiating current to the spark plug. A case of the ignition coil contains a circuit typically comprising a magnetically permeable core, a primary winding, and a secondary winding such that the mounting boss, low-voltage connector body, and high-voltage tower are secured to the case in a fixed relationship. In operation, a low voltage current is applied to the primary winding. The secondary winding is inductively coupled to the primary winding such that when the low voltage current to the primary winding is stopped by opening a switch, a high-voltage current is generated in the secondary winding which is passed to the spark plug. Ignition coils that have fixed geometries between the mounting boss, the low-voltage connector body, and the high-voltage tower are convenient to use in environments which produce internal combustion engines in high-volume, however, in service environments, i.e. automotive parts stores, service centers, automotive dealerships, and the like, it can be burdensome to maintain stock of the variations of ignition coils that are needed to service the variety of internal combustion engines that have been produced. Consequently, in order to minimize stock in a service environment, it would be more convenient to consolidate ignition coils that have equivalent circuits but different geometry between the mounting boss, the low-voltage connector body, and the high-voltage tower. This consolidation of ignition coils would provide for higher manufacturing volumes that would enable the manufacturer to keep a supply of service parts available longer, maintain higher quality, and be more cost effective for both the manufacturer and the customers.
In one known arrangement, an ignition coil is provided with a collapsible high-voltage tower which is initially at an extended position and is moved to a retracted position as the ignition coil is assembled to the internal combustion engine. However, the extent of adjustment of the high-voltage tower is two distinct lengths. Furthermore, the collapsible high-voltage tower does not make accommodations for differing geometric relationships of the mounting boss relative to the low-voltage connector body or orientation of the connector body.
What is needed is an ignition coil which minimizes or eliminates one or more of the shortcomings as set forth above.